Book binding machine



FIG. 1 is a front elevational view of a book binding machine showing my new design;

FIG. 2 is a left side elevational view with the power cord broken away for ease of illustration;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof; and

FIG. 5 is a top front right perspective view thereof. 

The ornamental design for a book binding machine, as shown and described. 